2019 TOYOTA PRIUS Forward Collision Avoidance Automatic Emergency Braking Problems

Since October 2023, my 2019 Toyota Prius has developed severe and unpredictable driving behavior after a regular brake service, which may have triggered or coincided with a software or ECU update. The car, which had been driving smoothly since I bought it in 2021, suddenly began showing false braking, steering interference, and lane instability — as if the car were trying to “correct” problems that didn’t exist. These interventions often happen on highways or during turns, creating serious safety risks for both driver and passengers. I’ve spent months and thousands of dollars replacing parts, performing alignments, and recalibrating sensors, including at Toyota dealerships. The problem persists because it is software-based, not mechanical. I discovered that in mid–2023, the NHTSA announced upcoming rules requiring Automatic Emergency Braking (AEB) with pedestrian detection by 2029. Around that same time, reports from multiple drivers (Toyota, Honda, Hyundai, Ford, Subaru) began to appear describing the...

I was idling at a parking space and went to turn off my car. The vehicle surged forward and the BRAKE sign came on. I pushed my brake to the floor and nothing happened. I was moving toward a brick wall so I put in in reverse and the car surged backwards. The BRAKE sign came on and I pushed the brake to the floor and again nothing happened and I ended up hitting the car behind me. I immediately took my car to the dealership where they kept it for 3 days and said they could find nothing wrong and it was safe to drive. I just got it back from having the body work done and am afraid to drive it as this might happen again or worse. I am reporting it to let you know and to see if this has occurred and been reported as happening...

VEHICLE INVOLVED IN A ACCIDENT. VEHICLE BRAKE SYSTEM DID NOT WORK. DRIVER HAD FOOT ON BRAKE PEDAL. ANTI COLLISION BREAK SYSTEM DID NOT WORK, VEHICLE SLID FOR 20FT INTO A STOPPED FOR. 2019 PRIUS WAS GOING 35 MPH BEFORE RISK OF COLLISION WAS REALIZED. SIGNIFICANT DAMAGE DONE ON PASSENGER SIDE BUMPER. NO AIR BAGS DEPLOYED.